A chemically amplified positive resist composition used for semiconductor microfabrication employing a lithography process contains an acid generator generating an acid by irradiation.
US 2006/0194982 A1 discloses a process for producing an acid generator represented by the formula (B1-1) which comprises reacting a salt represented by the formula (H1-5) with a salt represented by the formula (H1-4) obtained by reacting a salt represented by the formula (H1-2) with a compound represented by the formula (H1-3) as described below.

In the process disclosed in US 2006/0194982 A1, the salt represented by the formula (H1-4) is used as an intermediate for producing an acid generator.